Emergence of stable interfaces under extreme plastic deformation

• DOI: 10.1073/pnas.1319436111
• Publication Date: 2014-03-11T01:34:20Z
• Authors: Irene J. Beyerlein; Jason R. Mayeur; Shijian Zheng; Nathan A. Mara; Jian Wang; Amit Misra
• Keywords: 02 engineering and technology; 0210 nano-technology

Significance Many processing techniques, such as solid-state phase transformation, epitaxial growth, or solidification, can make nanocomposite materials with preferred crystallographic orientation relationships at internal interfaces. On the other hand, metal-working techniques can make composites in bulk quantities for structural applications but typically the resulting bimetal interfaces lack crystallographic order and are unstable with respect to heating. Using a metal-working roll-bonding technique, we find that at extreme plastic strains, the bimetal interfaces develop a remarkably ordered, preferred atomic structure. Using atomic-scale and crystal-plasticity simulations, we study the dynamical stability conditions responsible for this counterintuitive phenomenon. We show that the emergent interface corresponds to a unique stable state, which leads to exceptional mechanical, thermal, and irradiation stability of the nanocomposite.